The reductive singleelectrontransfer (SET) umpolung amination of aldehyde-derived hydrazones has been developed through visible-light-promoted photoredox catalysis. The ideal transformation of hydrazones into the corresponding hydrazonamide through selective carbon–hydrogen (C–H) bond functionalization represents one of the most step- and atom-economical methods. This SET umpolung strategy features
Oxidative Sulfonylation of Hydrazones Enabled by Synergistic Copper/Silver Catalysis
作者:Jun Xu、Chao Shen、Xian Qin、Jie Wu、Pengfei Zhang、Xiaogang Liu
DOI:10.1021/acs.joc.0c02249
日期:2021.3.5
A copper/silver-cocatalyzed protocol for oxidative sulfonylation of hydrazones is demonstrated. A wide range of β-ketosulfones and N-acylsulfonamides are directly synthesized in moderate to good yields. Our work provides a viable method for scalable preparation of β-ketosulfone derivatives that have found wide applications in the pharmaceutical industry.
Visible Light‐Induced [3+2] Cyclization Reactions of Hydrazones with Hypervalent Iodine Diazo Reagents for the Synthesis of 1‐Amino‐1,2,3‐Triazoles
作者:Jun‐Ying Dong、He Wang、Shukuan Mao、Xin Wang、Ming‐Dong Zhou、Lei Li
DOI:10.1002/adsc.202001436
日期:2021.4.13
In this study, visible‐light‐induced [3+2] cyclization reactions of hydrazones with hypervalent iodine diazo reagents as diazomethyl radical precursors are reported. Mild reaction conditions, a broad substrate scope, and excellent functional group compatibility were observed. Furthermore, the synthetic utility was demonstrated by gram‐scale synthesis and elaboration to several value‐added products
A simple and highly efficient method for the oxo-sulfonylation of aldehyde-derived hydrazones has been developed using sulfinic acid as a source of sulfonyl group and oxygen as a green oxidant under metal-free conditions at room temperature. The present C–O and N–S bond-forming difunctionalization strategy affords diversely functionalized N-acylsulfonamides in good yield. Experimental results suggest
Cu‐Catalyzed C(sp
<sup>2</sup>
−H)‐Trifluoromethylation of Aldehyde Hydrazones with Langlois Reagent
作者:Jatin Mehta、Puspa Aryal、V. Prakash Reddy
DOI:10.1002/ejoc.202100205
日期:2021.4.8
The C(sp2−H)‐trifluoromethylation of aromatic aldehyde N‐aminomorpholine hydrazones has been achieved under free‐radical conditions through Cu(II) catalysis using the cost‐effective Langlois reagent (sodium trifluoromethanesulfinate). The reaction tolerates a series of electron‐releasing as well as electron‐withdrawing substituents on the aromaticring.